Monte Carlo Simulation of Surface-Initiated Polymerization: Heterogeneous Reaction Environment
Bingbing Yang, Siwen Liu, Jiashu Ma, Yang Yang, Jiahao Li, Bang‐Ping Jiang, Shichen Ji, Xing‐Can Shen
Abstract
Computer simulations are widely applied to study surface-initiated polymerization (SIP), but in many studies, the chains are assumed to grow at the same speed, implying a homogeneous reaction environment. It has been ignored that SIP is a heterogeneous reaction. A simple stochastic reaction model is proposed in which the heterogeneity of the reaction environment is inherently considered by calculating the reaction probability of each active end individually. It was confirmed that SIP is a heterogeneous reaction, in which the inner chains grow in a monomer-poor region while the outer chains grow in a monomer-rich region. The different chain growths lead to a larger dispersity and a broader molecular weight distribution compared with the counterparts of an even chain growth system, which further affects properties like the density profile and the brush height. The results suggest that the heterogeneous reaction environment should be considered, especially when the grafting density is high.